The present invention relates to a stop mechanism for a knitting machine of the Rachel or Ketten type, the introduction of which on this type of machine results in a change in operation, allowing the detection of any of the threads breaking at the moment at which it occurs, causing the machine to stop automatically, in such a manner that one operator may with ease control several machines.
The advent of the device known as a stop mechanism, on looms generally resulted in a major revolution in the work as it allowed the control of several machines by one person without that person having to be at hand continuously at each machine. When there is a breakage in the thread, the machine stops completely so that the fault can be corrected and then the operation started up again without producing faults in the material being produced. The type of stop mechanism usually consists of blades which are fitted so as to ride on the thread, arranged in such a manner that at the moment of rupture of the thread two electrical contacts close so as to complete a circuit which generates a signal, which in turn stops the machine. This type of stop mechanism has to be placed manually one by one between each thread making up the cloth, this being an operation which is relatively time consuming but which is absolutely essential to the automation of these machines.
The machine of the Rachel ot Ketten type have in the past presented major difficulties in connection with the fitting of the stop mechanism, the only system being employed being the photoelectric cell. Apart from not giving a hundred percent detection of breakages, the photoelectric cell does not prevent the occurrence of faults in the material prior to the fault being detected which means that once the material has been made it must be submitted to a group of inspectors whose job it is to examine the faults made in the material and mend them, thus holding up the shipping of the material from the factory which slows down the rotation of the stock.